## Short explanation of TeX

[ambient page updated 11 Oct 05] ... [ home ] ... [ garrett@math.umn.edu ]

A description of a tiny subset of Donald Knuth's TeX markup system:

(0) Enclose all math in dollar signs, as $x^2-2x+1$. For _displayed_
math, meaning centered on a line by itself, use double dollar
signs: $$x^2+2x+1 = (x+1)^2$$

(1) Use caret for superscripts: $x^2$ is x-squared

(2) Use underbar for subscripts: $x_2$ is x-sub-two.

In both cases, the standard implementations of TeX do something that
may or may not surprise you: $x^23$ will be x-squared with a '3' right
after it, NOT x-to-the-23rd. To have larger exponents (more than a
single character), use _braces_ ("curly brackets"!?): $x^{23}$ would
be x-to-the-23rd. Similarly for subscripts.

(3) For keywords like "lim" inside "math mode", put a backslash in
front: $$\lim_{x \rightarrow \infty } x/(x^2+1) = 0$$

(4) The previous example also includes two other standard "escaped"
things, "\rightarrow" and "\infty" which are standard TeX
thingies. Guess what they stand for!?!?!?

(4') _Do_not_ use "->" for \rightarrow, since the "->" will not
typeset as well...

(5) There is also ${ x^2+1 \over x^2-2x+1 }$ which would create a
fraction x-squared-plus-1 over x-squared-minus-2x-plus-1. This can
also be written (in LaTeX and/or AMSTeX) as
$\frac{x^2+1}{x^2-2x+1}$

(6) Integral signs are $\int$. If you want limits on them, say lower
limit $a$ and upper limit $b$, do $\int_a^b$ (just like
superscripts and subscripts).

(7) Square root of blah is $\sqrt{blah}$

(8) not-equal-to is $\not=$

(9) greater-than-or-equal is $\ge$, while
less-than-or-equal is $\le$

(10) nth root of blah is ${\root {n} \of {blah}}$

(11) "degrees" maybe just make a superscript lowercase 'o':
"180 degrees" would be $180^o$ or $180^\circ$.

(12) \Delta and \delta for upper and lower-case delta
(13) \Theta and \theta for upper and lower-case theta
(14) \pi for pi

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page author. The contents of this page have not been reviewed or
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